This invention relates in general to internal combustion engines, and in particular relates to a rotary valve mechanism for controlling the flow of the intake and exhaust gases into and from the combustion chamber of such an engine.
Rotary valve mechanisms have previously been provided for use in controlling the flow of intake and exhaust gases into and from the cylinders of combustion engines. Certain of these mechanisms employ separate rotary valves for the intake and exhaust functions. The prior art rotary valve designs have included rotating cylinders or sleeves which control the flow of intake and exhaust gases. However, these valve designs have not been widely accepted in view of their many limitations and drawbacks. For example, previous rotary valve mechanisms have been relatively complicated and expensive, they have not provided optimum valve duration and overlap for efficient engine operation, and they have not achieved good volumetric efficiency with the result that performance is relatively poor and fuel consumption and exhaust gas emissions are relatively high. Moreover, previous rotary exhaust valves have been subject to failure because they have been continually exposed to the relatively high temperatures of the exhaust gases.
Accordingly, the need has been recognized for a new and improved rotary valve mechanism for use in internal combustion engines.